1. Field of the Invention
This invention is directed to vibratory separators; to screen assemblies for them; and, in certain particular aspects, to shale shakers and to screen assemblies for shale shakers.
2. Description of Related Art
Many typical vibratory separators and shale shakers have a container, carrier, housing, or basket to which is secured one or more screens or screen assemblies used for separating components of material fed to the vibratory separator or shale shaker. Vibrating apparatus vibrates the container and the vibrations are imparted to the screen(s) or screen assemblies secured to the container; or vibrating apparatus vibrates the screen(s) directly. Typically it is desirable to maximize vibration of the screen(s) while isolating equipment, objects, and structures adjacent the vibratory separator from the intense vibrations produced by the vibrating apparatus.
Often shale shakers are used offshore on rigs over salt water. Both the salt environment and the chemicals in drilling fluids processed by the shale shakers can contribute to the deterioration of screen assemblies.
There has long been a need, recognized by the present inventors, for a screen assembly for a vibratory separator and shale shaker which is durable; resistant to harsh environments and chemicals; provides effective screening over a temperature operation range; and is relatively light weight and easy to handle.